This invention relates to rotary valves or the like.
Rotary valves are normally employed between zones having a fluid pressure differential, and serve to permit solid materials to pass from one zone to another with a minimum fluid leakage between the zones. Known rotary valves generally comprise a housing having a bore, passages communicating with the bore and adapted to be coupled to the respective zones and a rotor which is a snug fit within the bore, the rotor defining an axial drive shaft, a pair of spaced end plates on the shaft and a series of radial vanes disposed between the end plates. Such valves are referred to hereinafter as rotary valves of the type described. A problem associated with known rotary valves is that material passing through the valve tends to enter the space between the peripheries of the end plates and the bore of the housing causing rapid wear. Where seals are provided between the bore and end plates, these are prone to break-down.